Electronic devices have been assembled to be light-weight and compact. The operation, integration, and complication of chips in electronic devices has increased over the years while the size of electronic devices or components used are getting thinner and smaller, and the pitch of soldering spots is also being reduced. These developments exacerbate an existing problem of solder spattering that occurs in solder reflow processes such that spattered solder often leads to undesired bridging and contamination due to the shortening pitch or distance between solders.
Generally, printed flexible electronics have been used in assembled electronic devices. Known printed flexible electronics have long relied on conductive adhesives such as solder and isotropic conductive adhesives (ICA) to form connections between conductive components or constructions. ICAs may be made with silver, copper, gold, or carbon and include a binder chemistry that includes epoxy, polyimide, or silicone, which are non-conductive. ICAs are typically utilized in processing because they include lower processing temperatures and higher print resolution. However, ICAs display performance limitations such as higher resistance, resistance gain with time, adhesion loss at high temperatures, joint cracking due to thermal expansion coefficient mismatch, and moisture absorption. Additionally, ICAs may be applied to electronic substrates and cured in a variety of mechanisms. In particular, ICAs may be snap cured, heat cured, room temperature cured, B-stage and two-component processed. These cure mechanisms may require that the electronic substrates to receive the ICA be in contact before the curing process.
Similarly, known solder reflow processes also may require that the electronic substrates be in contact with the solder before the curing process. In a conventional solder reflow process, a substrate or carrier is first prepared to receive electrical components. Then, at least one object to be soldered is placed on the carrier in which the object is positioned on the carrier through an application such as printing, dispensing, pick-and-place, plating, or other methods of application. A component to be joined is positioned on the solderable object or alternatively, a component that carries at least a solderable object is placed on the substrate. Afterwards, the substrate may be moved into a high-temperature reflow oven for carrying out a reflow process so as to have the solderable object heated and melted to bond to the substrate.
The conventional reflow process may include a preheating zone, a soaking zone, a reflow zone, and a cooling zone, which may be utilized on surfaces such as individual printed circuit boards or chips. Solder spattering may occur in different zones due to the use of different types of solder. Further, the solder reflow process may take additional time to allow the solder paste to properly cure, as the current state of this technology requires a particular dwell time before substantial curing may occur. In particular, current surface mount technology for a conventional reflow process may be relatively slow from the application to the curing time.
Disclosed are embodiments of an assembly, system, and method that may assist with solving the problems that exist in the prior art. The disclosed assembly, system, and method may improve the processing speed related to applying solder to a substrate and improve the deficiencies with ICAs for use in the electronics industry.